Many heavy, dense flowable or shifting products exert tremendous inside-to-outward pressure as they slip, shift, slide or flow within a box or tray. Often these excessive containment demands require that portions of a box or tray have extra layers of corrugated walls and/or be further secured with reinforcing/fastening materials such as: tape, glue, hot-melt adhesive, corrugator-applied string filaments & tapes or metal stitches/staples. When stitches/staples are used, there is dramatic stacking strength loss due to crushing and damage to the fluting, in the most strength-sensitive areas of a box or tray. Accordingly, a need exists for container which provides durability.